1. Field
This disclosure relates generally to non-volatile memories (NVMs), and more specifically, to resistive random access memories (ReRAMs).
2. Related Art
The development of resistive random access memories is promising due to features that offer many advantages. ReRAM cells have a dielectric that can, using electrical means, be made to have conductive filaments that establish a low resistance state. The process can be reversed whereby filaments are broken raising the resistance to a higher resistance state. One consideration with any semiconductor memory device is data density available in a given space or size of device.
With respect to a resistive RAM (ReRAM) device, the states of the resistive RAM device depend on the resistance of the device. For example, a higher resistance may correspond to a first state and a lower resistance may correspond to a second state. Tight resistance distribution is necessary to achieve multilevel storage capability which can significantly increase the data density. Therefore, it is desirable to improve control over the resistance distribution and to improve data retention for resistive RAM devices.
A further consideration with ReRAM in particular is the ability to achieve a consistent level of resistance for programming and erasing the memory cells.
Also, always a consideration is the ease with which any solution can be implemented. Since it is a different type of technology than normal semiconductor technology, the use of established techniques can be difficult in achieving a desired result for ReRAMs.
Accordingly there is a need for an ReRAM and a method of making the ReRAM that takes into account the considerations listed above.